E03
Potterton
Fan / Air Pressure Switch Fault
Boiler attempts to start then shuts down with E03, fan may run briefly, no ignition
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Faulty fan motor, Blocked flue or condensate trap, Defective air pressure switch, Split or blocked APS tubing
How to Fix / Troubleshooting
Safety first: Switch off the boiler and isolate from the mains. Do not operate the boiler with the case removed unless qualified.
User checks:
- Inspect the flue terminal outside for obstructions such as leaves, plastic bags, or nests; remove any blockage.
- Check that the condensate pipe is not frozen or blocked (especially in cold weather). Thaw gently with warm (not boiling) water if frozen.
- Reset the boiler once after clearing any obvious blockage.
Engineer checks:
- Verify the fan runs freely and quietly; check for seized bearings or debris in the fan housing.
- Test the air pressure switch (APS) for correct operation with a manometer or continuity tester while the fan runs.
- Inspect APS silicone tubes for splits, kinks, or blockages; replace tubing if hardened or damaged.
- Check flue integrity and correct installation per Potterton instructions.
If E03 persists, the fan or air pressure switch may need replacement by a Gas Safe engineer.
Advertisements
Repair Difficulty
Hard
4/5
Advertisements